Let’s talk about how to formulate your own salt bar recipe.

What is a salt bar?

A salt bar is typically a soap made with 50-100% of oil weight in salt. For example, if your salt bar recipe contains 32 oz. of coconut oil and 8 oz. of castor oil, then you would use 20 – 40 oz. of sea salt.

Why on earth would we want to make a salt bar?

Sea salt is purifying, drawing and acts as an astringent. This website explains how salt helps your skin here. It is great, especially, for acne.

Salt bars last FOREVER in the shower. In my experience, they last longer than regular bar soap. (This is a great selling point.)

Salt bars are hard! Salt soap cures out super hard. Salt bars are great for individual cavity molds that you can’t usually use with your regular recipe. The soap gets hard fast and will pop right out.

Superfat – 20%

What do we know about coconut oil in high percentages?

It can be drying. To combat the drying effects of using high coconut oil, we use a high superfat to leave oils unsaponified to make our soap moisturizing and nourishing. A typical superfat for a salt bar is 15-20%. I usually use 20%.

In a recipe not containing salt, this might make our soap mooshy or soft. But not in a salt bar. The salt helps to harden the soap. Even using a high superfat of 20%, this soap turns out super hard.

Salt – Which to use?

There are many different types of salt. Most any type of salt will work except dead sea salt. My favorite salt to use is fine sea salt. I get mine from Wholesale Supplies Plus.

Dead sea salt is actually more mineral than salt. It makes for a weepy, wet and yucky salt bar. Check out Amy’s post where she learned the hard way.

I don’t use Epson salt either. I’m not sure if that works or not…

Size doesn’t really matter. I prefer fine grain, but you can use up to large grain. It all melts with the warm water so isn’t that scratchy or exfoliating.

For varied color, you can use pink salt. I love this pink sea salt from Bramble Berry.

How much salt do you use?

You can use anywhere from 50% – 100% of your oil weight in salt.

Individual Cavity Molds

Salt bars get hard fast! It is best to use individual cavity molds when making salt bars. My favorite mold for salt bars this mold from Bramble Berry. I love the way the half cylinder bars fit in my hand.

If you pour salt soap into a loaf mold, you have to monitor it closely and cut it before it gets to hard. This can be 4 hours after you pour or 8. Sometimes it is hard to tell when they are ready to cut.

Let’s formulate a salt bar recipe!

Step 1 – How much soap will your molds hold?

I’m going to use the above Bramble Berry molds for this example. I want to fill up two of the molds. Each cavity holds 4 oz. for a total of 48 oz. of soap (oils + water + lye + salt). There is no easy formula to determine your oil amount because everyone uses a different amount of salt; some use 50%, some use 100%.

Step 2 – Formulate your base oils.

Let’s take a shot in the dark and start with a recipe that uses 24 oz. of coconut oil. Plug 24 oz. of coconut oil into soapcalc.net with a 20% superfat. For water, I ignore soap calc and when formulating salt bars, I simply multiply the lye amount by 3. So we end up with a recipe of :

Coconut oil – 24 oz.

Lye – 3.4

Water – 10.5

Step 3 – Determine how much salt you want to use.

Let’s see what it looks like with 50% salt and 100% salt.

50% Salt Bar

Coconut oil – 24 oz.

Lye – 3.4 oz.

Water – 10.5 oz.

Salt – 12 oz.

Total oz. (49.9 oz.)

100% Salt Bar

Coconut oil – 24 oz.

Lye – 3.4 oz.

Water – 10.5 oz.

Salt – 24 oz.

Total oz. (61.9 oz.)

Since our molds will hold 48 oz. of soap, the 50% salt bar will fit nicely. If we want to use 100% salt, we will need to scale the recipe down.

100% Salt Bar

Coconut oil – 19 oz.

Lye – 2.7 oz.

Water – 8.1 oz.

Salt – 19 oz.

Total oz. (48.8 oz.)

This 100% salt soap will fit in our molds.

Step 4 – Fragrance or Essential Oil

I calculate my rates based on the amount of oil in my recipe. For salt bars, I calculate based on the amount of oil + salt.

My standard rate for fragrance oil is .7-1 oz per pound of oil + salt. My standard rate for essential oil is .5 oz per pound of oil + salt. Rates vary depending on the strength of your oils, but these are good starting off points.

100% Salt Bar with fragrance oil at 1 oz. per pound of oil + salt

Coconut oil – 19 oz.

Lye – 2.7 oz.

Water – 8.1 oz.

Salt – 19 oz.

Total oil + salt = 40.7 oz.

FORMULA 40.7 / 16

Fragrance oil = 2.5 oz.

100% Salt Bar with essential oil at .5 oz. per pound of oil + salt

Coconut oil – 19 oz.

Lye – 2.7 oz.

Water – 8.1 oz.

Salt – 19 oz.

Total oil + salt = 40.7 oz.

FORMULA (40.7 / 16) * .5

Essential oil = 1.27 oz. (round to 1.3 oz.)

Step 5 – Add your colorant.

Most of the time colorants are simply a matter of preference. You can start with adding 1 teaspoon per pound of oils of mica, pigment or natural colorant and go up from there based on the color that you are trying to get.

So in the above example, you would add 2.5 teaspoons of a colorant and see how it looks. Adjust if more is needed to achieve the color that you want.

Step 1 – Wearing safety gear, make your lye solution by weighing out the lye and water into separate containers. Sprinkle the lye into the water while stirring. Stir until dissolved and set aside to cool.

“If you search the forum for salt bars and even read all through this thread you will find we tell people to Never Never grind salt, it can and will cause sharp shards that can lacerate the skin. I highly recommend you do not use those bars directly on your skin. Please heed our experience so you do not end up with a nasty laceration. At best, even some fine grind salt can cause a prickly bar or overly scrubby…”

In your opinion, will powdered salt included in a salt bar indeed do this?

Hi Amanda, this is Dewi from Indonesia. I found you are a great tutor. I just finished doing my last log of soap making, and I did sea salt soap based on your tutorial. Everything goes well only the soaps are weeping even after two days, but nicely hard though. How much longer will it take until they are all dry up. Thank you again and have a good day..

I have a lot of dentric sakt in hand right now, could I use this type of salt or would it be best to just wait for my five grain sea salt to arrive? Also, I was wondering if a 25% SF would be too much?

Big thanks for sharing this! So clear and action-appetizing. I was wondering – is it necessary to use a stick blender for this recipe? I know it’s a must have for soap making, but as it’s not on the equipment list and only comes in short bursts in the mixing 😀 I just feel like double checking. Thanks again

On the Soap Making Facebook page, everyone told me that the salt had to be dissolved in water before adding the lye. They said it wouldn’t harden the soap bar properly if added after the oils and lye were mixed. I added a teaspoon of salt per pound of oils to two different batches after the lye and oils had been combined, just as in your recipe above, to harden my bars. In both batches, the soap batter thickened to the consistency of room temperature butter almost immediately after adding the salt. It was hard to glop it into the molds fast enough, and I ended up with huge air pockets that no amount of tapping the molds could get out. Any thoughts?

Hi Amanda. I’m new to soapmaking (4th batch) and I just made your salt soap recipe. I added ground lavender and oatmeal, only less than a half ounce total. I used a bar mold, against your recommendation, because I recently made it myself and was dying to use it. and also fine Himalayan salt, which I just read was not a good choice. when I cut it after 7 hours, it crumbled pretty badly. Is there anyway I can re do? Reheat and repour? Also, it did not get real thick as you said it would. It poured kind of thin.
Thank you for any advice.

Hi Amanda, I made a batch with Himalayan Pink Salt a month back and the bars are still dripping water! Why does this happen? Does the climate have anything to do with this? I live in Kerala, India where the normal temperature is between 28 degree Celsius to 32C.

hi there, just wondering how many regular bars of soap your final recipe makes? Also, I’m waiting for my individual molds and was hoping to try this recipe before they arrive via post. I heard 1 litre milk containers work as soap molds. I read you’re not a fan of log molds but if I were to use it just for a test batch, what recipe/ratio of coconut oil and salt would you recommend (to best avoid the crumbling).

Hello Amanda 🙂
I really appreciate this..salt calculation seem so complicated. I have a question~
I have 24 oz trays as well (24 bars), I would like to make the 100 coconut oil to 50 salt recipe. To that I would like to add 4 oz fragrance (that may seem high but, my family likes a strong fragrance) Also two tablespoons of poppy seeds. I want to make 4 trays at once with no left over (waste). What would be the recipe please? I’ve been trying to work it out all day! *Feeling frustrated* Thank you.

Hi Amanda,
Thank you for sharing this.
This morning I made the exact size batch as you did and it is almost 9pm and my bars are still soft. I tried unfolding one and it came apart and is still wet feeling.
Any ideas what I could have done wrong?

I used sea salt. Not dead Sea salt.
I did replace one ounce of the coconut oil with caster oil. Do you think that could be the issue?
Some FB groups I’m in have suggested that I should have discounted the water.

Hi Sara! Replacing an ounce for an ounce shouldn’t make a difference. I honestly don’t know the issue. I make these all the time and they come out rock hard. How are they today?

Sara
August 1, 2016 at 9:31 am

They are much harder today. I was able to get them out of the mold without breaking apart. I think I was just jumping the gun. I always hear salt bars harden so fast so I thought 8hrs would be enough but I guess I should have waited longer.
Thanks for your help and the awesome blog!

I want to do the 80/10/10 recipe. My questions is for the liquid oils do I have to use 10% of the same oil or can I use two different liquid oils? I want to do 5% olive oil and 5% castor oil (which would total the 10% liquid)

Good day all. I want to go into soap production after goin through your blog I got some information which can help me improve on my soap making.but I want to ask
(1) What can I add to my soap to increase the quantity of the soap.
(2) what kind of salt can I use to harden my soap?like kind I add normal Hcl salt we use at home.
(3) what is the best foaming agent I can use to increase the lather.
Thank as I wait for you response.

I don’t know if you got a reply, but superfatting can be done through the SoapCalc. Technically, it’s the reduction of lye. So set your super fat percentage in the SoapCalc first at 5% and look at the amount of lye in the recipe, then change the super fat % to 20 and look at the new amount of lye. I had the same question until I figured it out through SoapCalc.

Hello,
Thanks so much for your post
I have been doing the salt bars for a year now and I encounter a problem with the bars sweating after cure. Can you help me, maybe there is a way to keep them from sweating cause the salt absorbs water.
Thank you

Amanda, I am interested in making a few batches of salt bar soap and was a little concerned after reading Soapmaking 101 about how quickly this can set up. I too have two Bramble Berry molds, the 9 bar cube and the 12 bar squares, how fast is fast? Is there enough time to get the soap into the individual cavities? Thanks!

There should be time to stir and pour. Be sure to soap cool; let the coconut oil cool down to room temp without going solid. I use individual molds all of the time and have enough time to pour. Let me know how it goes!